Training for sprint tri

Hi everyone!

I'm going to be doing a sprint tri (1km swim, 5km run, 20km ride) in September. I already ride occasionally and do strength training 3 times a week. I need to change this up to meet some new goals. I know this is a short race, and won't require a great deal of training. but this is my first tri, and is hopefully only the beginning to longer tris. So please take this into consideration.

Goals:
Increase V02max, as this is my weak area
More explosive power in my legs for hills, sprints, and running
Maintain current muscle mass as much as possible. I'd rather lose the fat.

Questions:
Should plyometrics be done once a week? or every other week?
Is doing strength/power training 3-4 times/wk with aerobic training 3-4 times/wk too much?
Should I do aerobic training on the same day or different day as strength/power training?
How do you integrate your strength training with aerobic training?